A subset of the repetitive sequences of the rat genome can be isolated by rat liver DNA-binding nonhistone proteins. The work in progress will determine the physical size of the DNA-bound repetitive sequences by S1 nuclease digestion of reassociated sequences. Sequence analysis of the protein-bound sequences will be investigated by restriction sensitivity. The abundant class of genes can be analyzed by mRNA complementary DNA hybridization. The significance is to demonstrate a subset of common repetitive sequences may be contiguous to a set or battery of genes.